+Indicator Methodology
The Annual Average UV Irradiance at Noon (mW/m2) is derived by aggregating the data from the Ozone Monitoring Instrument (OMI) (aboard the NASA Aura spacecraft) Level 2 Surface UV Irradiance Product. The dataset is grouped by county and year, focusing specifically on the UV irradiance measurements taken at solar noon. For each group, the mean of these noon measurements is calculated, excluding any days where data is missing. The resulting set of mean values represents the daily UV irradiance at noon for each day of the year. These values are then summed over the year for each group, and the sum is divided by the number of data-capturing days to obtain the annual average. This average is indicative of the intensity of UV irradiance experienced at the peak sun hours across the designated regions.
This calculation method is provided by the CDC National Environmental Public Health Tracking (https://ephtracking.cdc.gov/indicatorPages )